1. Field of the Invention
This invention relates to a method and apparatus for sewing, and more specifically to a method and apparatus by which a liquid is injected into the seam during sewing.
2. Prior Art
There presently is a need to seal the needle puncture holes in fabric, sheet plastic, and other materials after the material is sewn, by single, double or triple needle sewing machines. This sealing effect is particularly necessary on tent materials to prevent moisture penetration through the full-depth needle hole or through the needle hole in the top layer of material and then into the seam or seams between the two layers of material. A thread hole sealing process can also be used to act as a barrier for bacteria in sewn items such as hospital gowns, operating room gowns, and the like. Among the methods that have been tried to prevent leakage through the sewing needle holes are attempts such as spraying on exterior flexible air-drying sealing agents and applying the sealing fluid between seam layers before they are assembled for sewing. Also, attempts have been made to use sealing tapes before the material is sewn. None of the known methods have satisfactorily sealed the sewn area, and furthermore they have generated cosmetic or physical bad side effects such as puckering in a sewn joint, or else there has been an excessive amount of sealing material on the outside surfaces of the sewn material.